Predictive value of NT-proBNP for cardioversion in a new onset atrial fibrillation.

Objective: To detect the clinical use of N-terminal pro B-type natriuretic peptide (NT-proBNP) values for predicting cardioversion in a new onset atrial fibrillation (AF) in the emergency department.

Methods: NT-proBNP was measured in 200 patients admitted to the emergency department, in the observational unit with primary diagnosis of a new onset AF (<2 weeks). Cohort was divided into rate-control and rhythm-control groups according to the strategy used by the admitting physician. Patients treated with electric cardioversion were excluded. Primary endpoint was conversion to sinus rhythm during hospital admission.

Results: In rhythm and rate controls, NT-proBNP was lower in patients who restored sinus rhythm (P<0.001). Same result was observed even when logistic regression was used to adjust for differences at baseline clinical characteristics. NT-proBNP of less than 450 pg/ml was associated with cardioversion in both the groups (likelihood ratio of 0.19 for rate control, and 0.27 for rhythm control) whereas a value of more than 1800 pg/ml was associated with persistent AF at discharge (likelihood ratio of 2.02 and 2.01, respectively).

Conclusion: In the acute setting of a new onset AF, NT-proBNP seems to predict cardioversion in rate-control and rhythm-control strategies when it is less than 450 pg/ml or more than 1800 pg/ml. In this ranges of values it might help to allocate resources and plan for patient admission and further management. There is a grey area (450-1800 pg/ml) in which NT-proBNP did not seem to be clinically useful.